Preheat oven to 170° and a large rimmed baking sheet with parchment paper. Lightly grease with cooking spray. In a blender, blend watermelon until smooth.
Over a fine mesh strainer lined with cheesecloth (or paper towels), drain almost all liquid from watermelon purée until you have about 2 cups watermelon solids. (Save juice for another use!)
Step 3
In a medium bowl, whisk together watermelon solids, sugar, and lime juice.
Step 4
Divide mixture between prepared baking sheets, spreading with an offset spatula to make smooth even layers. Bake until dried out and no longer sticky, 3 to 4 hours.
Step 5
Using scissors, cut leather into vertical strips and roll up.
